On the transmission of crystallisation waves across the edge between the rough and faceted crystalline surfaces in superfluid 4He

TL;DR

This paper investigates how crystallisation waves behave when crossing the boundary between rough and faceted surfaces of superfluid helium-4, revealing how surface state affects wave transmission and reflection.

Contribution

It provides a detailed analysis of wave transmission and reflection at the boundary between rough and faceted crystal surfaces in superfluid helium-4, a novel exploration of surface state effects.

Findings

Transmission and reflection depend on surface state

Crystallisation wave behavior varies at the rough-faceted boundary

Insights into step dynamics at the crystal edge

Abstract

The wavelike processes of crystallisation and melting or crystallisation waves are well-known to exist at the crystal 4He surface in its rough state. Below the roughening transition temperature the crystal surface experiences the transition to the smooth faceted state and the crystallisation waves represent the propagation of a train of crystalline steps at the velocity depending on the crystal step height. Here we analyse the transmission and reflection of crystallisation waves propagating across the crystal edge separating the crystal surface in the rough and faceted states.